For two decades, Nunn has been floated as a potential vice presidential candidate by virtue of his national security credentials and conservative southern roots. And each time he has dis missed such talk out of hand, while the party’s nominees opted for more liberal choices from states more likely to go Democratic in November.

But this year, the personal and intellectual affinity between the presumptive Democratic nominee and the 69-year-old elder statesman – who abandoned a policy of not backing candidates in Democratic primaries when he endorsed Obama in April – makes him a real possibility as Obama’s running mate, according to interviews with current and former government officials who know both men.

“He sounds like he may be more open to it,” said Arnold Punaro, a retired Marine Corps general who served on Nunn’s Senate staff for 24 years and remains in close contact with his former boss. “He has never before endorsed anybody. That was a surprise to me.”

And if not VP, then perhaps Secretary of Defense? After all, he was a vocal opponent of the Iraq invasion in 2003, and as mentioned above, he understands the need for finding common ground to “close the gap between the global threats from nuclear, biological and chemical weapons and the global response.”

Here’s Nunn on Charlie Rose in 2007…

Seems like a decidedly post-partisan guy to me, and that would fit nicely with Obama’s message for change. And while some are brining up Nunn’s age (currently 69), I think age is less important to voters than a genuine willingness to bring a different tone to Washington.